JP2013071599A - Bearing device for wheel with built-in in-wheel motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device for a wheel with a built-in in-wheel motor, capable of reducing a space in an axial direction while ensuring lighter weight and rigidity of the bearing device for a wheel.SOLUTION: In the bearing device, a hub ring 13 and a bearing case 14 are formed of an aluminum alloy by die casting. An output member 6 constituting a decelerator 3 includes: a connecting shaft 35 which is inserted into the hub ring 13 on the outer circumference of the shaft via a serration; an annular base part 37 formed with a large diameter at the inner side of the connecting shaft; and a holding part 54 comprising a pair of flanges 38, 39 which are disposed to protrude outward in a radial direction from the annular base part and to oppose to each other in an axial direction, and in which a pinion gear 32 is housed, and a bridge 40 axially connecting the flanges to each other. The side face 54a of the holding part 54 of the output member 6 comes in contact with the larger end face 21a of an inner ring 21 in a directly butted state, and the output member 6 is fixed to the hub ring 13 to be capable of transmitting torque, by a fixing nut 36 screwed to the end of the connecting shaft 35.

Description

  The present invention relates to a wheel bearing device for rotatably supporting a wheel, and an in-wheel motor built-in wheel bearing device in an electric vehicle in which the wheel bearing device, a speed reducer, and a motor are combined.

  In recent years, as a countermeasure for reducing the environmental load of automobiles, a shift from a conventional driving type using an engine to a driving type using a motor has been studied. Under such circumstances, an in-wheel type motor-integrated wheel bearing device in which a wheel bearing, a reduction gear, and a motor are combined is attracting attention as a wheel bearing device for an electric vehicle. When the in-wheel type motor-equipped wheel bearing device is used as a driving wheel of an electric vehicle, each wheel can be individually driven to rotate, so that a large-scale power transmission mechanism such as a conventional propeller shaft or a differential is not required. Can be made lighter and more compact.

  As an example of the in-wheel type motor built-in wheel bearing device, one shown in FIG. 9 is known. This in-wheel type motor-equipped wheel bearing device includes a wheel bearing device 101 that rotatably supports a wheel (not shown), a motor 102 as a rotation drive source, and a hub that decelerates the rotation of the motor 102 to reduce the rotation of the motor 102. The speed reducer 103 that transmits to the wheel is disposed on the central axis O of the wheel.

  The motor 102 is configured by a radial gap type motor in which a radial gap is provided between a stator 105 fixed to a cylindrical motor casing 104 and a rotor 107 attached to an output shaft 106. The output shaft 106 is rotatably supported by the rolling bearings 108 and 108 including a pair of deep groove ball bearings with respect to the motor casing 104. The opening on the inner side of the motor casing 104 is closed with a cap 109.

  The reduction gear 103 is a cycloid reduction gear, and includes an input shaft 111 having an eccentric shaft 110, a plurality of outer pins 113 passed between the reduction gear casing 112 and the motor casing 104, and a drive shaft (output member). 114 includes a plurality of inner pins 115 and two curved plates 118 and 119 that are rotatably supported by the pins 113 and 115 via rolling bearings 116 and 117 made of cylindrical roller bearings. . The curved plates 118 and 119 are formed in a wavy trochoid curve having a gentle outer shape, and are attached to the eccentric shaft 110. The outer pin 113 is rotatably supported by rolling bearings 120 and 120 including a pair of needle roller bearings, and the outer pin 113 guides the eccentric motion of the curved plates 118 and 119 on the outer peripheral side.

  The input shaft 111 is coupled to the output shaft 106 of the motor 102 via a spline 111a and is integrally rotated. When the output shaft 106 of the motor 102 rotates, the eccentric shaft 110 attached to the input shaft 111 that rotates integrally therewith rotates, and the curved plates 118 and 119 engaged with the eccentric shaft 110 perform an eccentric motion. The rotation of the rotor 107 is smoothly and efficiently transmitted as a rotational movement of the drive shaft 114 with a large reduction ratio.

  The two curved plates 118 and 119 are mounted on the eccentric shaft 110 of the input shaft 111 with a phase difference of 180 ° so that the eccentric motion is canceled out, and on each side of the eccentric shaft 110, the curved plates 118 and 119 are mounted. Counterweights 121 and 121 that are eccentric in the direction opposite to the eccentric direction of the eccentric shaft 110 are mounted so as to cancel the vibration caused by the eccentric motion. The input shaft 111 is rotatably supported by a rolling bearing 122 formed of a deep groove ball bearing with respect to a drive shaft 114 described later.

  The wheel bearing device 101 is externally inserted through an inner member 125 including a hub wheel 123 and an inner ring 124 press-fitted into the hub wheel 123, and the inner member 125 via double rows of balls 126 and 126. The outer member 127 is provided.

  The hub wheel 123 integrally has a wheel mounting flange 128 for mounting a wheel at one end, and has an inner rolling surface 123a on the outer periphery and a small-diameter stepped portion 123b extending in the axial direction from the inner rolling surface 123a. A serration 123c for torque transmission is formed on the inner periphery. The inner ring 124 is formed with the other inner rolling surface 124a on the outer periphery, and is press-fitted into the small-diameter step portion 123b of the hub ring 123 via a predetermined squeeze.

  The outer member 127 integrally has a vehicle body mounting flange 127b attached to the reduction gear casing 112 via a fixing bolt 112a on the outer periphery, and a plurality of outer members 127 facing the inner rolling surfaces 123a and 124a of the inner member 125 on the inner periphery. The outer rolling surfaces 127a and 127a of the row are integrally formed. Between these rolling surfaces 127a, 123a and 127a, 124a, double rows of balls 126, 126 held in a cage 129 are accommodated so as to roll freely.

  The drive shaft 114 constituting the speed reducer 103 includes a flange portion 130 to which the inner pin 115 is attached, a cylindrical shoulder portion 131 extending in the axial direction from the flange portion 130, and a shaft extending in the axial direction from the shoulder portion 131. The part 132 is integrally formed. A serration 132a meshing with the serration 123c of the hub wheel 123 is formed on the outer periphery of the shaft portion 132, and a male screw is formed at this end portion. The drive shaft 114 is brought into contact with the hub wheel 123 until the shoulder portion 131 abuts the end surface of the inner ring 124. The drive shaft 114 and the hub wheel 123 are coupled to each other in the axial direction so as to transmit torque (fixed torque 133 is fixed by a fixed nut 133 fitted inside and screwed to the male screw) (see, for example, Patent Document 1). ).

JP 2011-117529 A

  In such a conventional structure, an oil seal 134 is mounted in an annular space formed between the outer member 127 of the wheel bearing device 101 and the shoulder 131 of the drive shaft 114, and the gear sealed in the speed reducer 103. Sealed so that oil does not leak into the bearing. However, in order to install this oil seal 134, a mounting space is required in the axial direction. For this reason, the whole apparatus enlarges and a weight increases. In order to avoid this, it is conceivable to reduce the size of the wheel bearing device 101. However, in this case, when the bearing rigidity is reduced and a moment load is applied, the curved plate 118 constituting the speed reducer 103, The displacement of 119 increases, and the contact state between the curved plates 118 and 119 and the outer pin 113 may be poor.

  In addition, since the wheel bearing device 101 that supports the drive shaft 114 of the speed reducer 103 is elastically deformed by the load from the road surface to the wheels, the rolling bearing 122 becomes the original axis of the input shaft 111 and the output shaft 106. However, the motor casing 104 is hardly affected by the load from the wheels, and the coaxiality of the two rolling bearings 108 and 122 is deteriorated and tilted. For this reason, an uneven load is likely to act on these rolling bearings 108 and 122, not only lowering the durability and noise of the rolling bearings 108 and 122 but also lowering the rotational accuracy of the input shaft 111 and the output shaft 106. There was a problem such as.

  The present invention has been made in view of such a conventional problem, and provides an in-wheel motor-equipped wheel bearing device that can reduce the axial space while ensuring weight reduction and rigidity of the wheel bearing device. The purpose is to provide.

  In order to achieve such an object, the invention according to claim 1 of the present invention includes a wheel bearing device for rotatably supporting a wheel, a motor arranged coaxially with respect to the central axis of the wheel, A reduction gear provided with an input shaft driven by the output of the motor, a cylindrical portion, and a front end portion whose central portion is opened at an outer end portion thereof, and the reduction gear and the motor are accommodated. And a housing is fitted into the opening at the front end of the housing, fastened to the front end by a fixing bolt, and the input shaft is provided by a pair of rolling bearings on both sides in the axial direction of the reducer. An in-wheel motor-equipped wheel bearing device supported, wherein the wheel bearing device integrally has a wheel mounting flange for mounting the wheel at one end portion, and extends in the axial direction on the outer periphery. Shape And a wheel bearing fitted to the hub ring and the bearing case, the wheel bearing comprising an outer ring integrally formed with a double row outer raceway on the inner periphery, A pair of inner rings each having an inner race surface facing the outer race surface of the double row on the outer periphery, and a double row rolling element housed between the inner race and the outer race so as to roll freely. And an in-wheel motor-equipped wheel bearing device having a seal attached to an opening of an annular space formed between the outer ring and the inner ring, wherein the hub ring and the bearing case are made of an aluminum alloy. And an output member that constitutes the speed reducer includes a coupling shaft portion that is inserted into the outer periphery of the hub wheel via serrations, an annular base portion that is formed on the inner side of the coupling shaft portion and has a large diameter, and Projecting radially outward from the annular base to hold the reduction gear A holding portion, and a side surface of the holding portion is in direct contact with the large end surface of the inner ring, and the output member is torqued to the hub wheel by a fixing nut screwed to the end portion of the coupling shaft portion. It is fixed so that it can be transmitted.

  Thus, a wheel bearing device for rotatably supporting the wheel, a motor arranged coaxially with respect to the central axis of the wheel, a speed reducer having an input shaft driven by the output of the motor, It has a cylindrical part and a front end part whose center part is open at the end part on the outer side, and a housing for housing the speed reducer and the motor. A bearing case is fitted into the opening part of the front end part of the housing. And an in-wheel motor-equipped wheel bearing device in which the input shaft is supported by a pair of rolling bearings on both sides in the axial direction of the speed reducer, and fastened to the front end portion by a fixing bolt. A hub wheel integrally having a wheel mounting flange for mounting a wheel at one end thereof and having a small-diameter stepped portion extending in the axial direction on the outer periphery; and a wheel bearing fitted to the hub wheel and a bearing case; Consists of A wheel bearing of the outer ring in which the outer race surface of the double row is integrally formed on the inner periphery, and a pair of inner rings in which the inner race surface facing the outer race surface of the double row is formed on the outer periphery, A double row rolling element housed in a freely rolling manner between both rolling surfaces of the inner ring and the outer ring, and an seal provided in an opening of an annular space formed between the outer ring and the inner ring. In the wheel-type motor built-in wheel bearing device, the hub wheel and the bearing case are made of an aluminum alloy, and the output member constituting the speed reducer is inserted into the hub wheel through serrations on the outer periphery via a serration, and An annular base portion having a large diameter on the inner side of the coupling shaft portion, and a holding portion that protrudes radially outward from the annular base portion to hold the reduction gear, and the side surface of the holding portion is the inner ring Abutted directly against the large end face and screwed to the end of the coupling shaft Because the output member is fixed to the hub wheel so that torque can be transmitted by the fixing nut, the inner ring diameter can be increased compared to conventional devices, and the output member can be abutted against the output member at a one-step larger diameter position. It is possible to provide an in-wheel motor-equipped wheel bearing device that can reduce the axial space while ensuring the rigidity of the wheel bearing device.

  Preferably, if the hub ring and the bearing case are subjected to a precipitation hardening process in which the hub ring and the bearing case are hardened by heat treatment, the strength is increased and the amount of aluminum used is reduced to achieve weight reduction. can do.

  According to a third aspect of the present invention, the speed reducer includes a sun gear provided on the outer periphery of the input shaft, a ring gear fixed to the housing and disposed coaxially with the sun gear, A ring gear and a sun gear are arranged at equal intervals in the circumferential direction and are arranged at a plurality of locations, and are composed of planetary gears that are rotatably supported by the holding portion, and the holding portion has a predetermined interval. And a pair of flanges that are arranged opposite to each other in the axial direction and accommodate the pinion gear, and a bridge that connects the pair of flanges in the axial direction, and both ends of the pinion pins are fixed to the pair of flanges. If the pinion gear is rotatably supported by the pinion pin via a needle roller bearing, the output member can be smoothly rotated, and the input shaft and Rotational accuracy of the fitting fixed motor rotor is improved les.

  According to a fourth aspect of the present invention, a shaft hole coaxial with the coupling shaft portion is formed on the inner side end face of the holding portion, and the shaft hole has a depth reaching the annular base portion. In addition, if the input shaft is inserted into the shaft hole and supported by a pair of rolling bearings, the input shaft is cantilevered by the output member, so that the support structure can be simplified and the wheel Since the vibrations and impacts transmitted to the output member are simultaneously applied to both rolling bearings in the same manner, it is possible to prevent an unbalanced load from acting on either rolling bearing.

  According to a fifth aspect of the present invention, the speed reducer is disposed on the inner diameter side of the motor, and a housing portion for the speed reducer and the motor is partitioned by a partition provided in the housing. The partition may be formed of a partition base formed coaxially with the opening inside the front end of the housing, and a cup-shaped partition member fixed to the partition base.

  Further, as in the invention described in claim 6, if the partition base and the partition member are integrally formed on the housing, the number of parts can be reduced, the assembly process can be simplified, and the cost can be reduced. it can.

  Further, as in the invention according to claim 7, if the annular base portion of the output member is fitted and inserted into the small diameter step portion of the hub wheel via a seal ring made of an elastic member, the lubricating oil in the reduction gear is reduced. Leakage to the outside can be prevented, and contamination of the surrounding environment can be prevented.

  Further, as in the invention described in claim 8, if the bearing case is fitted and inserted into the front end portion of the housing via a seal ring made of an elastic member, it is possible to prevent intrusion of rainwater or the like from the outside. it can.

  In addition, as in the invention according to claim 9, if a washer made of a light alloy is interposed in at least one of the large end face of the inner ring, the output member, and the hub ring and the fixing nut, an aluminum alloy Since the bearing case made of steel has a larger coefficient of linear expansion than the steel outer ring, inner ring and output member, if the temperature rises while the vehicle is running, the amount of expansion of the bearing case increases and the internal clearance of the wheel bearing becomes larger. Although it may increase, it is possible to suppress an increase in internal clearance with a light alloy washer.

  Further, as in the invention described in claim 10, if an oil seal is attached to the opening of the annular space formed between the front end portion of the housing and the inner ring, the outer side of the wheel bearing device Unlike conventional devices in which an oil seal is mounted between the member and the shoulder of the output member, the axial space can be further reduced, and the lubricating grease sealed inside the bearing by a single seal Since it is possible to prevent leakage to the outside and intrusion of lubricating oil, contamination, etc. into the bearing from the reducer side, it is possible to reduce rotational torque due to seal sliding contact

  Moreover, if the diameter of one rolling element is set larger than the diameter of the other rolling element among the double row rolling elements as in the invention described in claim 11, the bearing rigidity is increased. be able to.

  Further, as in the invention described in claim 12, if the number of the other rolling elements is set larger than the number of the one rolling elements, the bearing rigidity can be increased.

  According to a thirteenth aspect of the present invention, a bolt hole is formed at a circumferentially equidistant position of the wheel mounting flange of the hub wheel, and the wheel mounting flange is connected to the wheel mounting flange by a wheel bolt screwed into the bolt hole. If the wheel is fixed, it will not only be possible to replace it easily in the market if a defect such as a scratch occurs on the threaded part of the wheel bolt. Therefore, it is not necessary to secure the space on the inner side of the wheel mounting flange, and the repairability is improved, and the axial space can be reduced by that amount, and the weight and the size can be reduced while ensuring the rigidity. it can.

  An in-wheel motor-equipped wheel bearing device according to the present invention includes a wheel bearing device for rotatably supporting a wheel, a motor arranged coaxially with respect to the central axis of the wheel, and an output of the motor. A reduction gear including an input shaft to be driven, a cylindrical portion, and a front end portion whose central portion is opened at an end portion on the outer side thereof, and a housing in which the reduction gear and the motor are accommodated, An in-wheel in which a bearing case is fitted into the opening at the front end of the housing and fastened to the front end by a fixing bolt, and the input shaft is supported by a pair of rolling bearings on both sides in the axial direction of the speed reducer Type motor built-in wheel bearing device, wherein the wheel bearing device integrally has a wheel mounting flange for mounting the wheel at one end, and a small-diameter step portion extending in the axial direction is formed on the outer periphery. A hub wheel and a wheel bearing fitted in the bearing case. The wheel bearing includes an outer ring in which a double row outer raceway is integrally formed on the inner periphery, and an outer periphery. A pair of inner races formed with an inner raceway facing the outer raceway surface of the double row, and a double row rolling element accommodated between the inner race and the outer race so as to roll freely. In the in-wheel type motor-integrated wheel bearing device including a seal attached to an opening of an annular space formed between the outer ring and the inner ring, the hub ring and the bearing case are formed of an aluminum alloy. In addition, an output member constituting the speed reducer includes a coupling shaft portion that is fitted on the outer periphery of the hub wheel via serrations, an annular base portion that has a large diameter on the inner side of the coupling shaft portion, Projecting radially outward from the base to hold the reduction gear And the output member is torque-transmitted to the hub wheel by a fixing nut screwed onto the end of the coupling shaft. Because it is fixed as possible, the diameter of the inner ring can be made larger and the output member can be abutted against the output member at a position where the diameter is one step larger than that of the conventional device, and the shaft is secured while reducing the weight and rigidity of the wheel bearing device. It is possible to provide an in-wheel motor-equipped wheel bearing device that can reduce the directional space.

It is a longitudinal section showing a 1st embodiment of a bearing device for wheels with a built-in in-wheel type motor concerning the present invention. (A) is the principal part enlarged view which shows the wheel bearing apparatus and reduction gear of FIG. 1, (b) is the principal part enlarged view which shows one seal part of (a), (c) is (a). It is a principal part enlarged view which shows the other seal part of this. (A) is a principal part enlarged view which shows the motor part of FIG. 1, (b) is a principal part enlarged view which shows the seal part of (a). It is a principal part enlarged view which shows the wheel bearing apparatus and output member of FIG. It is a principal part enlarged view which shows the modification of FIG. It is a principal part enlarged view which shows the modification of the wheel bearing apparatus of FIG. It is a principal part enlarged view which shows the modification of the wheel bearing apparatus of FIG. It is a principal part enlarged view which shows the other modification of the wheel bearing apparatus of FIG. It is a longitudinal cross-sectional view which shows the conventional bearing apparatus for in-wheel type motor built-in wheels.

  A wheel bearing device for rotatably supporting a wheel; a motor arranged coaxially with respect to the central axis of the wheel; a speed reducer having an input shaft driven by the output of the motor; and a cylindrical portion; The outer end has a front end that is open at the center, and includes a housing that houses the speed reducer and the motor, and a bearing case is fitted into the opening at the front end of the housing. The in-wheel motor-equipped wheel bearing device is fastened to the front end portion by a fixing bolt, and the input shaft is supported by a pair of rolling bearings on both sides in the axial direction of the speed reducer. The apparatus has a hub wheel integrally having a wheel mounting flange for mounting the wheel at one end and a small diameter step portion extending in the axial direction on the outer periphery, and the hub wheel and the bearing case are fitted. car This wheel bearing has an outer ring in which a double-row outer rolling surface is integrally formed on the inner periphery, and an inner rolling surface that faces the outer rolling surface of the double-row on the outer periphery. A pair of inner rings, a double row of rolling elements housed between the rolling surfaces of the inner ring and the outer ring, and an opening in an annular space formed between the outer ring and the inner ring. In an in-wheel motor-equipped wheel bearing device including a mounted seal, the hub wheel and the bearing case are formed by die casting from an aluminum alloy, and the speed reducer is configured by a planetary gear. An output member comprising a coupling shaft portion that is fitted on the outer periphery of the hub wheel via serrations, an annular base portion having a large diameter on the inner side of the coupling shaft portion, and a radially outer portion from the annular base portion. Protruding axially at a predetermined interval A pair of flanges that are disposed opposite to each other and that accommodate the pinion gear, and a holding portion that includes a bridge that connects the pair of flanges in the axial direction, and a side surface of the holding portion of the output member is a large portion of the inner ring. The output member is fixed to the hub wheel so as to be able to transmit torque by a fixing nut that is in direct contact with the end face and is screwed to the end of the coupling shaft portion.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a first embodiment of an in-wheel motor-equipped wheel bearing device according to the present invention, and FIG. 2A is a main portion showing the wheel bearing device and the speed reducer of FIG. (B) is an enlarged view of the main part showing one seal part of (a), (c) is an enlarged view of the main part showing the other seal part of (a), and FIG. 1 is an enlarged view of the main part showing the motor part of FIG. 1, FIG. 4B is an enlarged view of the main part showing the seal part of FIG. 1, and FIG. 4 is an enlarged view of the main part showing the wheel bearing device and output member of FIG. FIG. 5 is an enlarged view of a main part showing a modification of FIG. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  The in-wheel motor-equipped wheel bearing device includes a wheel bearing device 1 that rotatably supports a wheel (not shown), a motor 2 that serves as a rotational drive source, and a motor 2 that decelerates rotation of the motor 2 to be described later. The reduction gear 3 that transmits to the hub wheel 13 and the housing 4 that accommodates the reduction gear 3 and the motor 2 are the main components and are arranged on the central axis O of the wheel. The hub wheel 13 of the wheel bearing device 1 is rotated by an output member 6 coaxial with the input shaft 5 of the speed reducer 3.

  The housing 4 is made of an aluminum alloy such as A6063TE or ADC12, and includes a cylindrical portion 7 and a front end portion 8 at an outer end portion thereof. The central portion is opened, and the wheel bearing device 1 is provided in the opening portion 9. The vehicle body mounting flange 14 b is fastened to the front end portion 8 by a fixing bolt 17.

  A partition base 8a having a larger diameter is formed coaxially with the opening 9 inside the front end 8 of the housing 4, and a cup-shaped partition member 10 is fixed to the partition base 8a with bolts (not shown). ing. A center hole 11 is formed at the center of the partition member 10, and the center hole 11 faces an outer diameter surface of a rotor support member 45 described later via an annular space. A partition wall 12 is configured by the partition wall base portion 8a and the partition wall member 10 connected to the partition wall base portion 8a. The partition wall 12 has a function of partitioning the housing 4 into a housing space for the motor 2 on the outer diameter side and a housing space for the reduction gear 3 on the inner diameter side. If the partition base 8a and the partition member 10 are formed integrally with the housing, the number of parts can be reduced, the assembly process can be simplified, and the cost can be reduced.

  The wheel bearing device 1 is referred to as a first generation for driving wheels, and as shown in an enlarged view in FIG. 2A, the hub wheel 13 and a bearing case (for example, a knuckle case) 14 are fitted between them. And a combined wheel bearing 15.

  The hub wheel 13 integrally has a wheel mounting flange 16 for mounting a wheel (not shown) at an end portion on the outer side, and is formed with a small-diameter step portion 13b extending in the axial direction via a shoulder portion 13a. A serration (or spline) 13c for torque transmission is formed around the circumference. Further, hub bolts 16 a are planted at the circumferentially equidistant positions of the wheel mounting flanges 16.

  The hub wheel 13 is formed by die casting from an aluminum alloy such as A6061 or ADC12, and is heated to a high temperature to form a solid solution, followed by a quenching process in which it is rapidly cooled in water, and then kept at room temperature or at a low temperature ( A so-called precipitation hardening treatment, in which a large lattice strain is generated in the precipitate phase and hardened by a heat treatment composed of an age hardening treatment (tempering treatment) that is heated to 100 to 200 ° C. for precipitation, is performed. As a result, the mass productivity can be improved and the cost can be reduced. In addition, the strength can be increased to reduce the amount of aluminum used, and the weight can be reduced.

  The bearing case 14 is formed by die casting from an aluminum alloy such as A6061 or ADC12, and is attached to the front end 8 of the housing 4 via the fixing bolt 17 on the outer periphery, and the flange 14a is attached to the outer end. And an annular groove 14c is formed at the inner end of the inner periphery. An outer ring 19 of a wheel bearing 15 to be described later is internally fitted until it abuts against the flange portion 14a, and is positioned and fixed in the axial direction by a retaining ring 18 attached to the annular groove 14c. Similar to the hub wheel 13, the bearing case 14 is formed by die casting from an aluminum alloy such as A6061 or ADC12 and subjected to precipitation hardening.

  The wheel bearing 15 includes an outer ring 19 in which double row outer rolling surfaces 19a, 19a are integrally formed on the inner periphery, and an inner rolling surface 20a facing the double row outer rolling surfaces 19a, 19a on the outer periphery. A pair of inner rings 20, 21 formed with 20 a and double row rolling elements (balls) 23, 23 accommodated in a cage 22 between the rolling surfaces 19 a, 20 a so as to roll freely. . The outer ring 19, the inner rings 20, 21 and the rolling element 23 are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core part by quenching.

  Seals 24 and 25 are attached to the openings of annular spaces formed between the outer ring 19 and the inner ring 20 on the outer side, and between the front end 8 of the housing 4 and the inner ring 21 on the inner side, respectively. Leakage of the lubricating grease enclosed inside is prevented, and lubricating oil, contamination, etc. from the reduction gear 3 side are prevented from entering the bearing.

  As shown in an enlarged view in FIG. 2B, the outer side seal 24 is an integrated seal composed of a core metal 26 fitted in the outer ring 19 and a seal member 27 joined to the core metal 26. It consists of The core metal 26 is formed by pressing from a steel plate such as an austenitic stainless steel plate (JIS standard SUS304) or a cold-rolled steel plate (JIS standard SPCC system), and is predetermined on the outer periphery of the outer ring 19 on the outer side. It is press-fitted through a shimeshiro.

  On the other hand, the seal member 27 is made of synthetic rubber such as NBR (acrylonitrile-butadiene rubber) and is integrally joined to the core metal 26 by vulcanization adhesion. The seal member 27 is formed in a bifurcated shape, and integrally includes a main lip 27a and a grease lip 27b that are in sliding contact with the outer diameter surface of the inner ring 20 via a predetermined radial shimiro.

  In addition to NBR, the material of the seal member 23 is excellent in heat resistance and chemical resistance, such as HNBR (hydrogenated acrylonitrile butadiene rubber), EPDM (ethylene propylene rubber), etc., which are excellent in heat resistance. Examples thereof include ACM (polyacrylic rubber), FKM (fluororubber), and silicon rubber.

  As shown in an enlarged view in FIG. 2 (c), the inner-side seal 25 includes a metal core 28 fitted in the front end portion 8 of the housing 4 and a seal member 29 joined to the metal core 28. It is composed of an integral seal. The cored bar 28 is formed by pressing from a steel plate such as an austenitic stainless steel plate or a cold rolled steel plate, and is press-fitted into the inner periphery of the front end 8 via a predetermined squeezing.

  On the other hand, the seal member 29 is made of synthetic rubber such as ACM, and is integrally joined to the cored bar 28 by vulcanization adhesion. This seal member 29 integrally has a main lip 29a slidably in contact with the outer diameter surface of the inner ring 21, and a grease lip 29b extending incline toward the bearing inner side (outer side). A garter spring 29c is externally fitted to ensure a predetermined lip tension. Here, since synthetic rubber such as ACM having excellent heat resistance and chemical resistance is used for the seal member 29, compatibility with the lubricating oil is good and oil leakage can be prevented over a long period of time. In addition to ACM, examples of the material of the seal member 29 include HNBR, EPDM, and the like that are excellent in heat resistance, FKM, silicon rubber, and the like.

  In addition, although the wheel bearing 15 comprised by the double row angular contact ball bearing which used the ball for the rolling element 23 was illustrated here, it was not restricted to this but was comprised by the double row tapered roller bearing using a tapered roller. It may be a thing.

  The reduction gear 3 is of a planetary gear type. As shown in FIG. 2A, the input shaft 5, the output member 6, a sun gear 30 integrally formed on the outer diameter surface of the input shaft 5, On the outer periphery, the ring gear 31 is disposed along the inner diameter surface of the boundary portion between the partition wall base portion 8a and the partition wall member 10 and fixed via the knock pin 31a, and the ring gear 31 and the sun gear 30 are equally spaced in the circumferential direction. And pinion gears 32 arranged at three locations. The pinion gear 32 is supported by a pinion pin 34 via a needle roller bearing 33.

  The output member 6 is integrally provided with a coupling shaft portion 35 at the outer end. The coupling shaft 35 has a serration (or spline) 35 a that is engaged with the serration 13 c of the hub wheel 13 on the outer periphery, and a male screw 35 b formed at the end of the serration 35 a, and is fastened by a fixing nut 36.

  On the inner side of the coupling shaft portion 35, an annular base portion 37 having a diameter larger than that of the coupling shaft portion 35 is formed, and a pair of flanges 38 and 39 project from the annular base portion 37 radially outward. The pair of flanges 38 and 39 are opposed to each other in the axial direction with a space slightly larger than the width dimension of the pinion gear 32, and a bridge 40 for connecting the pair of flanges 38 and 39 in the axial direction is surrounded by a circumference. It is provided at three locations with equal orientation. The pair of flanges 38 and 39 have a carrier function in the planetary gear type reduction gear 3.

  By providing the bridge 40 in the circumferentially equidistant position, the output member 6 is smoothly rotated, and as a result, the rotation accuracy of the rotor 46 of the motor 2 described later can be improved through the output member 6 and the input shaft 5. .

  A shaft hole 41 coaxial with the coupling shaft 35 is formed on the end face of the flange 39 on the inner side of the pair of flanges 38 and 39. The shaft hole 41 has a depth that reaches the annular base portion 37. The input shaft 5 is inserted into the shaft hole 41 and is supported by a pair of rolling bearings 42 and 42 formed of deep groove ball bearings.

  A pair of flanges 38 and 39 and three bridges 40 in the circumferential direction are provided with pinion gear accommodating portions partitioned in the circumferential direction. The pinion gear 32 is accommodated in these accommodating portions, and a pair of pinion gears 34 is interposed via the pinion pins 34. The flanges 38 and 39 are integrally connected. A locking hole 34a that penetrates in the radial direction is formed at the end of the pinion pin 34, and is fixed by a set screw (not shown) that is screwed into a screw hole 39a formed in the flange 39 on the inner side. Yes.

  Thrust plates 43 and 43 are interposed between both side surfaces of each pinion gear 32 and the pair of flanges 38 and 39 in order to ensure smooth rotation of the pinion gear 32. A pair of rolling bearings 42 and 42 are mounted in an annular space formed between the inner diameter surfaces of the pair of flanges 38 and 39 and the outer diameter surface of the input shaft 5 facing the inner diameter surfaces. It is supported by the member 6. Thus, since the input shaft 5 is cantilevered by the output member 6, the support structure can be simplified, and vibrations and impacts transmitted from the wheel to the output member 6 are both in the rolling bearings 42. , 42 are simultaneously loaded in the same manner, so that it is possible to prevent an unbalanced load from acting on either of the rolling bearings 42, 42, and to improve rotational accuracy and durability. In addition, the generation of rotating noise can be suppressed.

  As shown in FIG. 3A, the motor 2 is a radial gap type in which a radial gap is provided between a stator 44 fixed to the cylindrical portion 7 of the housing 4 and a rotor 46 attached by a rotor support member 45. This is a brushless DC motor.

  The rotor support member 45 includes a cylindrical support portion 45a fitted to the inner diameter portion of the rotor 44, a disc portion 45b extending radially inward along the partition wall 12 from the cylindrical support portion 45a, and the disc portion 45b. A cylindrical fixing portion 45c formed at the inner end of the cylinder is provided. The rotor support member 45 is fixed to the input shaft 5 via a key 45d locked to the cylindrical fixing portion 45c.

  An oil seal 47 is mounted in an annular space formed between the center hole 11 of the partition member 10 and the cylindrical fixing portion 45 c of the rotor support member 45. As shown in an enlarged view in FIG. 3B, the oil seal 47 is constituted by an integral oil seal including a cored bar 48 and a seal member 49 joined to the cored bar 48. The core metal 48 is formed by pressing from a steel plate such as an austenitic stainless steel plate or a cold rolled steel plate.

  On the other hand, the seal member 49 is made of synthetic rubber such as ACM, and is integrally joined to the core metal 48 by vulcanization adhesion. The seal member 49 integrally includes a main lip 49a that is slidably in contact with the outer diameter surface of the cylindrical fixing portion 45c, and a sub lip 49b that is inclined and extended toward the inner side. A garter spring 49c is externally fitted to ensure the force. The oil seal 47 prevents the lubricating oil on the speed reducer 3 side from moving to the motor 2 side, and the motor 2 side is maintained in a dry state. Therefore, the lubricating oil may hinder the rotation of the rotor 46. Avoided. In addition to ACM, examples of the material of the seal member 49 include HNBR, EPDM, and the like that are excellent in heat resistance, FKM, silicon rubber, and the like.

  As shown in FIG. 3A, the motor 2 and the speed reducer 3 are within the range of the axial length of the cylindrical portion 7 of the housing 4 except for the rear end portion (end portion on the inner side) of the input shaft 5. Therefore, the cylindrical portion 7 is closed by a cover 51 attached to the rear end portion of the cylindrical portion 7 via a seal ring 50 made of an O-ring or the like. The seal ring 50 is made of a synthetic rubber such as ACM.

  A rotation sensor 52 is disposed at the center of the cover 51. The rotation sensor 52 is a resolver, the sensor stator 52 a is fixed to the cover 51, and the sensor rotor 52 b is attached to the input shaft 5.

  A lead wire (not shown) of the sensor stator 52a is connected to a connector insertion portion (not shown) provided outside. As the rotation sensor 52, a Hall element or the like can be used in addition to the resolver. The rotation angle of the input shaft 5 detected by the rotation sensor 52 is input to the control circuit via a signal line cable (not shown) and used for rotation control of the motor 2.

  Here, in this embodiment, as shown in FIG. 2A, the output member 6 has a coupling shaft portion 35 formed on the outer end portion and a large diameter on the inner side of the coupling shaft portion 35. An annular base portion 37 formed and a pair of flanges 38 and 39 projecting radially outward from the annular base portion 37. As shown in an enlarged view in FIG. 4, the annular base portion 37 of the output member 6 is an ACM. The hub ring 13 is inserted into the small-diameter step portion 13b through a seal ring 53 made of synthetic rubber or the like. And the side surface 54a of the holding part 54 which consists of a pair of flanges 38 and 39 and the bridge 40 which connects these pair of flanges 38 and 39 to each other in the axial direction is in direct contact with the large end surface 21a of the inner ring 21 on the inner side. It is in contact. Specifically, the large end surface 21a on the inner side of the wheel bearing 15 is abutted against the side surface 54a of the holding portion 54 so as to overlap with the hole into which the pinion pin 34 is inserted. Thereby, compared with the conventional device, the inner ring 21 on the inner side can be increased in diameter and abutted against the output member 6 at the position of one step larger diameter, and the axial space can be secured while ensuring the rigidity of the wheel bearing device 1. In addition, it is possible to provide an in-wheel motor-equipped wheel bearing device that improves the rotational accuracy of the input shaft 5 and the durability of the bearing that supports the input shaft 5.

  A pinion pin 34 that supports the pinion gear 32 is inserted so as not to protrude from the end face of the flange 38. Thereby, the contact | abutting with the inner ring | wheel 21, the large end surface 21a, and the side surface 54a of the holding | maintenance part 54 is not prevented, but a proper butting | matching state can be maintained.

  Unlike the conventional device in which an oil seal is mounted between the outer member of the wheel bearing device and the shoulder of the drive shaft (output member), the seal 25 slides with the outer diameter of the inner ring 21. As a result, the axial space can be further shortened, and the lubricating grease sealed inside the bearing by the single seal 25 is leaked to the outside. Can be prevented from entering, so that the rotational torque due to the seal sliding contact can be reduced.

  Further, the annular base portion 37 of the output member 6 is fitted into the small diameter step portion 13 b of the hub wheel 13 through the seal ring 53, and the bearing case 14 is fitted into the front end portion 8 of the housing 4 through the seal ring 55. Since it is inserted, it is possible to prevent rainwater and the like from entering from the outside, to prevent the lubricating oil in the speed reducer 3 from leaking to the outside, and to prevent the surrounding environment from being contaminated. These seal rings 53 and 55 are O-rings made of synthetic rubber such as ACM.

  As shown in FIG. 5, a seal ring 53 may be interposed between the corner portion of the annular base portion 37 of the output member 6 and the end portion of the small diameter step portion 13 b of the hub wheel 13. Thereby, the process of the annular groove for mounting the seal ring 53 on the outer peripheral surface of the annular base part 37 can be omitted, the assembly process can be simplified and the cost can be reduced along with the simplification of the process steps. be able to.

  The in-wheel type motor-equipped wheel bearing device according to the present invention is configured as described above, and the operation thereof will be described with reference to FIG.

  When the motor 2 is driven by operating the accelerator of the driver's seat, the input shaft 5 is rotated integrally with the rotation of the rotor 46, and the motor output is input to the speed reducer 3. When the sun gear 30 rotates integrally with the input shaft 5, the speed reducer 3 revolves while the pinion gear 32 rotates. When the pinion gear 32 rotates at a reduced speed at this revolution speed, the output member 6 is rotated at a deceleration output having a predetermined reduction ratio. Then, the hub wheel 13 of the wheel bearing device 1 is rotated integrally with the coupling shaft portion 35 of the output member 6, and the wheel attached to the wheel mounting flange 16 of the hub wheel 13 is driven.

  The input shaft 5 is supported by a pair of rolling bearings 42 and 42 on both sides of the pinion gear 32 and rotates. Since these rolling bearings 42 and 42 are both attached to the flanges 38 and 39 integral with the output member 6, as described above, the radial transmission from the wheel to the output member 6 via the wheel bearing device 1 is performed. Directional vibrations and shocks are simultaneously applied to both rolling bearings 42 and 42 in the same manner, and any rolling bearings 42 and 42 can be prevented from applying an unbalanced load.

  Further, since both ends of the pinion pin 34 of the pinion gear 32 are supported by the pair of flanges 38 and 39, the support rigidity becomes high, and good engagement between the pinion gear 32, the ring gear 31 and the sun gear 30 can be obtained. And durability can be improved.

  FIG. 6 is a modification of the above-described wheel bearing device (FIG. 1). Note that this embodiment basically differs from the above-described embodiment only in part of the configuration of the wheel bearing device, and other parts and parts having the same parts or parts having the same functions are denoted by the same reference numerals. Detailed description is omitted.

  In the present embodiment, the output member 6 is fitted and inserted into the hub wheel 13 constituting the wheel bearing device 1 via the serration 35a. Here, the holding portion 54 of the output member 6 is in contact with the large end surface 21 a of the inner ring 21 on the inner side via a washer 56. The fixing nut 36 is screwed to the screw portion 35 b of the coupling shaft portion 35 of the output member 6 with a predetermined torque via a washer 57.

  Washers 56 and 57 are made of a light alloy such as an aluminum alloy. Since the aluminum alloy bearing case 14 has a larger coefficient of linear expansion than the steel outer ring 19, inner rings 20, 21 and the output member 6, if the temperature rises while the vehicle is running, the amount of expansion of the bearing case 14 is large. Thus, the internal clearance (axial clearance) of the wheel bearing 15 may increase, but the increase of the internal clearance can be suppressed by these washers 56 and 57.

  FIG. 7 shows a modification of the wheel bearing device 1 of FIG. This embodiment basically differs from the above-described embodiment only in the specifications of the left and right rolling elements of the wheel bearing, and the same reference numerals are given to the same parts or parts having the same function. Detailed description will be omitted.

  The wheel bearing device 58 is referred to as a first generation for driving wheels, and includes a hub wheel 13, a bearing case 14, and a wheel bearing 59 fitted therebetween. The wheel bearing 59 includes an outer ring 60 in which double row outer rolling surfaces 60a and 19a are integrally formed on the inner periphery, and an inner rolling surface 61a facing the double row outer rolling surfaces 60a and 19a on the outer periphery. , 20a, a pair of inner rings 61, 21 and double row rolling elements 23a, 23 accommodated in the cages 22a, 22 between the rolling surfaces 60a, 61a and 19a, 20a. It has. The outer ring 60, the inner rings 61 and 21, and the rolling elements 23a and 23 are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC to the core part by quenching.

  Seals 24 and 25 are attached to the openings of annular spaces formed between the outer ring 60 and the inner ring 61 on the outer side and between the front end 8 of the housing 4 and the inner ring 21 on the inner side, respectively. Leakage of the lubricating grease enclosed inside is prevented, and lubricating oil, contamination, etc. from the reduction gear 3 side are prevented from entering the bearing.

  Here, in this embodiment, the pitch circle diameters of the double row rolling elements 23a, 23 are the same, but the diameter do of the outer side rolling element 23a is larger than the diameter di of the inner side rolling element 23. In addition to setting (do> di), the number Zi of the inner-side rolling elements 23 is set to be larger (Zi> Zo) than the number Zo of the outer-side rolling elements 23a.

  In the wheel bearing device 58 having such a configuration, the pitch circle diameters of the double-row rolling elements 23 a and 23 are the same, but the diameter do of the outer rolling element 23 a is larger than the diameter di of the inner rolling element 23. Since the number Zi of the inner side rolling elements 23 is set to be larger than the number Zo of the outer side rolling elements 23a, the life of the outer side bearing row can be effectively utilized by utilizing the bearing space. The bearing rigidity of the inner side portion can be increased as compared with the outer side.

  FIG. 8 is another modification of the wheel bearing device 1 of FIG. The wheel bearing device 62 is called a first generation for driving wheels, and includes a hub wheel 63, a bearing case 14, and a wheel bearing 15 fitted therebetween. The hub wheel 63 integrally has a wheel mounting flange 16 at an end portion on the outer side, a small-diameter step portion 13b extending in the axial direction via the shoulder portion 13a is formed, and a serration 13c for torque transmission is formed on the inner periphery. Has been. The hub ring 63 is formed by die-casting from an aluminum alloy such as A6061 or ADC12 and subjected to precipitation hardening.

  Here, in the present embodiment, bolt holes 64 a to which the wheel bolts 64 are fastened are formed at the circumferentially equidistant positions of the wheel mounting flanges 16. Then, the brake rotor 65 and the wheel 66 are mounted on the wheel mounting flange 16 of the hub wheel 63 and then fixed by the wheel bolt 64. As a result, when a defect such as a scratch is generated in the threaded portion of the wheel bolt 64, not only can it be easily replaced in the market, but the wheel can be replaced for bolt replacement in the market as in the past. It is no longer necessary to secure the space on the inner side of the mounting flange 16, and repairability is improved, and the space in the axial direction can be reduced by that amount, and light weight and compactness can be achieved while securing rigidity.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including. In the present embodiment, an example of a knuckle is shown as a bearing case, but the present invention is not limited to this.

  An in-wheel type motor-equipped wheel bearing device according to the present invention includes a wheel bearing device, a reduction gear, and a motor combined, and the wheel bearing device includes a wheel bearing fitted between a hub wheel and a bearing case. It can be applied to the first generation structure provided.

DESCRIPTION OF SYMBOLS 1, 58, 62 Wheel bearing apparatus 2 Motor 3 Reduction gear 4 Housing 5 Input shaft 6 Output member 7 Cylindrical part 8 Housing front end part 8a Partition base 9 Housing opening 10 Partition member 11 Center hole 12 Partition member 13 Partition 13 , 63 Hub wheel 13a Shoulder portion 13b Small diameter step portion 13c, 35a Serration 14 Bearing case 14a ridge portion 14b Car body mounting flange 14c Annular groove 15, 59 Wheel bearing 16 Wheel mounting flange 16a Hub bolt 17 Fixing bolt 18 Retaining ring 19, 60 Outer ring 19a, 60a Outer rolling surface 20, 21, 61 Inner ring 20a, 61a Inner rolling surface 21a Large end surface 22, 22a Cage 23, 23a Rolling element 24 Outer side seal 25 Inner side seal 26, 28, 48 Core 27, 29, 49 Seal members 27a, 29a, 49a Main lip 27b, 9b Grease lip 29c, 49c Garter spring 30 Sun gear 31 Ring gear 31a Knock pin 32 Pinion gear 33 Needle roller bearing 34 Pinion pin 34a Locking hole 35 Coupling shaft portion 35b Male thread 36 Fixing nut 37 Annular base 38, 39 Flange 39a Screw hole 40 Bridge 41 Shaft hole 42 Rolling bearing 43 Thrust plate 44 Stator 45 Rotor support member 45a Cylindrical support portion 45b Disc portion 45c Cylindrical fixing portion 45d Key 46 Rotor 47 Oil seal 49b Sub lip 50, 53, 55 Seal ring 51 Cover 52 Rotation sensor 52a Sensor Stator 52b Sensor rotor 54 Holding part 54a Side surfaces 56 and 57 of the holding part Washer 64 Wheel bolt 64a Bolt hole 65 Brake rotor 66 Wheel 101 Wheel bearing device 102 Mo 103 Reduction gear 104 Motor casing 105 Stator 106 Output shaft 107 Rotor 108 Rolling bearing 109 Cap 110 Eccentric shaft 111 Input shaft 111a Spline 112 Reduction gear casing 112a Fixing bolt 113 Outer pin 114 Drive shaft 115 Inner pins 116, 117, 120, 122 Roller bearing 118, 119 Curved plate 121 Counterweight 123 Hub wheel 123a, 124a Inner rolling surface 123b Small diameter step 123c, 132a Serration 124 Inner ring 125 Inner member 126 Ball 127 Outer member 127a Outer rolling surface 127b Car body mounting flange 128 Wheel mounting flange 129 Cage 130 Flange part 131 Shoulder part 132 Shaft part 133 Fixing nut 134 Oil seal di Diameter of rolling element on inner side do Straight of rolling element on outer side Diameter O Drive wheel center axis Zi Number of inner side rolling elements Zo Number of outer side rolling elements

Claims (13)

A wheel bearing device for rotatably supporting the wheel;
A motor disposed coaxially with respect to the central axis of the wheel;
A reduction gear having an input shaft driven by the output of the motor;
A cylindrical portion, and a front end portion whose central portion is opened at an end portion on the outer side thereof, and a housing in which the speed reducer and the motor are accommodated,
A bearing case is fitted into the opening of the front end of the housing and fastened to the front end by a fixing bolt,
The in-wheel type motor built-in wheel bearing device in which the input shaft is supported by a pair of rolling bearings on both axial sides of the speed reducer,
The wheel bearing device integrally includes a wheel mounting flange for mounting the wheel at one end, a hub wheel having a small-diameter step portion extending in the axial direction on the outer periphery, and the hub wheel and the bearing case. Consisting of fitted wheel bearings,
The wheel bearing includes an outer ring in which a double row outer rolling surface is integrally formed on an inner periphery, and a pair of inner rings in which an inner rolling surface facing the outer surface of the double row is formed on an outer periphery. A double-row rolling element that is rotatably accommodated between the rolling surfaces of the inner ring and the outer ring, and a seal that is attached to an opening of an annular space formed between the outer ring and the inner ring. In-wheel type motor-equipped wheel bearing device provided,
The hub wheel and the bearing case are made of an aluminum alloy, and an output member constituting the speed reducer is coupled to the outer periphery of the hub wheel via serrations, and an inner side of the joint shaft portion An annular base portion having a large diameter and a holding portion that protrudes radially outward from the annular base portion to hold the reduction gear, and the side surface of the holding portion directly contacts the large end surface of the inner ring. The in-wheel type motor-equipped wheel bearing device is characterized in that the output member is fixed to the hub wheel so as to be able to transmit torque by a fixing nut that is brought into contact with each other at the end of the coupling shaft portion. .   The in-wheel motor-equipped wheel bearing device according to claim 1, wherein the hub wheel and the bearing case are subjected to a precipitation hardening process for hardening by heat treatment.   The speed reducer includes a sun gear provided on the outer periphery of the input shaft, a ring gear fixed to the housing and arranged coaxially with the sun gear, and an equal interval in the circumferential direction between the ring gear and the sun gear. And a plurality of planetary gears that are rotatably supported by the holding portion, the holding portions are arranged opposite to each other in the axial direction at a predetermined interval, and the pinion gear is It consists of a pair of flanges to be accommodated and a bridge that connects the pair of flanges in the axial direction. Both ends of the pinion pin are fixed to the pair of flanges, and the pinion gear is needle-like to the pinion pin. The in-wheel motor-equipped wheel bearing device according to claim 1, which is rotatably supported via a roller bearing.   A shaft hole coaxial with the coupling shaft portion is formed on an end surface on the inner side of the holding portion. The shaft hole has a depth reaching the annular base portion, and the input shaft is inserted into the shaft hole. The in-wheel motor-equipped wheel bearing device according to claim 1, wherein the wheel bearing device is supported by a pair of rolling bearings.   The reduction gear is disposed on the inner diameter side of the motor, and the reduction gear and the motor accommodating portion are partitioned by a partition wall provided in the housing, and the partition wall is formed on the inner side of the front end portion of the housing. The in-wheel type motor-equipped wheel bearing device according to claim 1, comprising a partition base formed coaxially with the portion and a cup-shaped partition member fixed to the partition base.   The in-wheel type motor-integrated wheel bearing device according to claim 5, wherein the partition base and the partition member are formed integrally with the housing.   The in-wheel type motor-integrated wheel bearing device according to claim 1, wherein the annular base portion of the output member is fitted and inserted into a small-diameter step portion of the hub wheel via a seal ring made of an elastic member.   The in-wheel type motor-integrated wheel bearing device according to claim 1, wherein the bearing case is fitted and inserted into a front end portion of the housing via a seal ring made of an elastic member.   2. The in-wheel type motor-integrated wheel bearing device according to claim 1, wherein a washer made of a light alloy is interposed in at least one of the large end surface of the inner ring, the output member, and the hub ring and the fixing nut.   2. The in-wheel motor-equipped wheel bearing device according to claim 1, wherein an oil seal is attached to an opening portion of an annular space formed between a front end portion of the housing and the inner ring.   2. The in-wheel type motor-integrated wheel bearing device according to claim 1, wherein a diameter of one of the rolling elements in the double row is set larger than a diameter of the other rolling element.   The bearing device for in-wheel motor built-in wheels according to claim 11 with which the number of said other rolling elements is set up more than the number of one rolling elements.   The bolt hole is formed in the circumferentially equidistant position of the wheel mounting flange of the hub wheel, and the wheel is fixed to the wheel mounting flange by a wheel bolt screwed into the bolt hole. Bearing device for wheels with built-in in-wheel motor.

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